Fantasies (6)
'fantasies' is the definition.
('illusion' can be a synonym of 'fantasy')
This is all the clue.
'fantasies' is the definition.
(dream is a kind of fantasy)
This is all the clue.
(Other definitions for dreams that I've seen before include "Thoughts and visions during sleep" , "Fancies" , "Reveries or cherished aspirations" , "Fantasy ambitions" , "Imaginings" .)